POWER TRANSMISSION MECHANISM, WHEELCHAIR, CHAIN BLOCK DEVICE, AND ROTATION DRIVING UNIT

摘要

PROBLEM TO BE SOLVED: To limit rotation of a power transmission device without degrading transmission efficiency.SOLUTION: The power transmission mechanism includes a first carrier member 23 rotatable around the axis of a ring gear member 10, a second carrier member 33 rotating around the axis of the ring gear member 10, a first planetary gear member 20 meshed with the ring gear member 10, and a second planetary gear member 30 meshed with the first planetary gear member 20. The first planetary gear member 20 and second planetary gear member 30 are meshed at a position where faces including each axis and the axis of the ring gear member 10 intersect with each other, and a rotation regulation means 25 to regulate relative rotation in such a direction that the axes of the first planetary gear member 20 and the second planetary gear member 30 are separated, and to allow rotation in such a direction that the axes of the first planetary gear member 20 and the second planetary gear member 30 approximate is configured, thus relatively rotating the ring gear member 10 and the second carrier member 33.